1. Field of the Invention
The present invention relates to a room lamp fixing structure for attaching a room lamp of a motor vehicle to a ceiling with sufficiently high positioning accuracy. More particularly, the present invention relates to a room lamp fixing structure in which a room lamp and a ceiling trim are modularized, and the resultant module is temporarily fixed to the ceiling framework of a car body first and is thereafter permanently fixed thereto, the room lamp fixing structure allowing highly accurate permanent fixing of the room lamp module.
2. Description of the Prior Art
Prior art room lamp fixing structures are disclosed in, for example, Japanese Patent Laid-Open Publication Nos. Hei 11-115628 and Hei 11-348657.
In these conventional room lamp fixing structures, a room lamp and a ceiling trim are modularized, and the resultant module is temporarily fixed to the ceiling framework of a car body first and is thereafter permanently fixed thereto. In this construction, a common hook is shared between the temporary fixing and the permanent fixing. That is, the prior art construction is composed of a room lamp with a harpoon-shaped hook and a support bracket for covering the room lamp, which has upper and lower stepped portions and is caught by the hook inserted thereinto. In this prior art construction, the hook is inserted into the support bracket so as to be caught in the lower stepped portion of the bracket, and thereby the support bracket and the room lamp are temporarily fixed to each other. Then, in the automobile assembly line, the module, obtained by modularizing the support bracket and the room lamp, is attached to the ceiling framework of the motor vehicle. At this time, by further inserting the room lamp into the support bracket, the hook is caught in the upper stepped portion thereof, and thereby the room lamp and the support bracket are permanently fixed to each other, and they are fixed to the ceiling framework.
This prior art construction, however, when the module composed of the room lamp and the support bracket is attached to the ceiling framework of the motor vehicle, pays no regard to positioning accuracy of the module relative to the ceiling. Particularly, in the prior art construction, since a common hook is used to fix the module temporarily and permanently, if positional deviation occurs during the temporary fixing, the hook is not capable of compensating for the positional deviation during the permanent fixing. This makes satisfactory permanent fixing impossible.
Furthermore, in general, an error occurs when the ceiling is attached to the car body. Therefore, when the module is fixed to the ceiling, this error needs to be compensated for. In the conventional fixing structure, however, when the module is permanently fixed to the ceiling, the attaching operation is out of sight from underneath (blind operation). This makes it difficult to achieve the permanent fixing so that the error is compensated for.
An object of the present invention is to provide a room lamp fixing structure in which, during the permanent fixing, the room lamp and the ceiling trim kept in the temporary fixing state are positioned with ease and sufficiently high accuracy, and the positioning mechanism is structurally simple and inexpensive.
Another object of the present invention is to provide a room lamp fixing structure in which, even if an error occurs when the ceiling is attached to the car body and the attachment is performed as a blind operation, the relative error is successfully compensated for and thus the module composed of the room lamp and the ceiling trim is attached to the ceiling properly.
To achieve the above objects, according to the present invention, a room lamp fixing structure is composed of temporary fixing means provided for a room lamp and a ceiling trim and permanent fixing means provided for the room lamp and a ceiling framework of a car body. The room lamp fixing structure includes a ceiling trim, a room lamp, a temporary fixing means, and a permanent fixing means. The ceiling trim has a recess for housing the room lamp whose side surface is so inclined as to become gradually narrow from the opening portion to the bottom portion. The room lamp has, in its side surface, a guide projection for positioning the room lamp and the ceiling trim during the permanent fixing by abutting against the slant side surface of the recess. The temporary fixing means allows the room lamp and the ceiling trim to be temporarily fixed to each other. The permanent fixing means allows, by permanently fixing the room lamp to the ceiling framework, the room lamp and the ceiling trim kept in the temporary fixing state to be fixed to the ceiling framework.
In this room lamp fixing structure, the temporary fixing means is composed of an engagement pawl provided in the room lamp and an edge of an engagement clearance hole provided in the ceiling trim. At the edge of the engagement clearance hole of the ceiling trim a slit is formed. The engagement pawl is, after passing through the slit and the engagement clearance hole, detachably caught in the edge of the engagement clearance hole, thereby achieving the temporary fixing.
Further, in the room lamp fixing structure, between the room lamp and the bottom portion of the recess facing with each other a gap is formed to cope with changes in the board thickness of the ceiling trim.
Still further, in the fixing structure, the permanent fixing means is composed of a spring retainer and an abutting portion provided in the room lamp and a stationary portion provided in the ceiling framework. The spring retainer is elastically caught in the stationary portion, thereby achieving the permanent fixing.
With the above-described construction, in the room lamp fixing structure according to the present invention, the room lamp is housed in the recess to be temporarily fixed to the ceiling trim by the temporary fixing means, and subsequently the room lamp in its temporary fixing state is permanently fixed to the ceiling framework by the permanent fixing means. Then, the guide projection of the room lamp abuts against the slant side surface of the recess. By the resultant guiding effect exerted by the guide projection and the slant side surface, the room lamp and the ceiling trim kept in the temporary fixing state are positioned. At the same time, the room lamp and the ceiling trim kept in the temporary fixing state are fixed to the ceiling framework.
As described above, the fixing structure according to the present invention has separately-provided temporary and permanent fixing means and is so designed that both fixing means can compensate for positional deviation during the permanent fixing. This makes it possible to compensate for the positional deviation occurring with the temporary fixing during the permanent fixing. Therefore, according to the present invention, there is provided a room lamp fixing structure in which the room lamp and the ceiling trim kept in the temporary fixing state are positioned with ease and sufficiently high accuracy, and the positioning mechanism is structurally simple and inexpensive.